Equipment for manufacturing an easily polymerizable compound such as (meth)acrylic acid or (meth)acrylate employs column equipment such as a distillation column for crude (meth)acrylic acid or crude (meth)acrylate or a decomposition reaction distillation column for recovering (meth) acrylic acid or the like by decomposing a high boiling point substance.
In such column equipment, part or whole of a column top gas may be cooled and liquefied in a column top gas condenser for liquefaction, to thereby form a reflux or a distillate. Further, a gas (vent gas) containing valuable substances, which were not condensed in the column top gas condenser, may be cooled in a vent gas condenser, to thereby recover the valuable substances.
When a gaseous easily polymerizable substance is condensed and liquefied in a condenser, an inhibitor-less solution without a polymerization inhibitor is formed. Thus, such a condenser for handling an easily polymerizable substance conventionally employs a technique of spraying a solution containing a polymerization inhibitor into the condenser for suppressing formation of a polymerized product in a condensate, to thereby include the polymerization inhibitor in the condensate (see JP 2000-344688 A, for example).
When such a conventional spray for spraying a solution containing a polymerization inhibitor is provided, a tube for introducing a solution containing the polymerization inhibitor into the spray is provided with a supporter for suppressing vibration of the tube and the spray in use because of a volume of liquid flow, a weight of the tube, or the like.
In a conventional vertical fixed tube plate-type condenser 50 to which a gas containing an easily polymerizable compound is supplied from above as shown in FIG. 5 for example, a polymerization inhibitor supply tube 53 which supplies a polymerization inhibitor to a spray 52 such that the polymerization inhibitor is sprayed on an entire top face of a tube plate 51, which is dividing a gas passage and a cooling medium passage, above the tube plate 51 from the spray 52; is supported inside the condenser 50 from below by a supporter 54. Further as shown in FIG. 6 for example, the polymerization inhibitor supply tube 53 is supported by a supporter 55 from above inside the condenser 50. A gas supplied to the condenser 50 is condensed in a cooling tube 56.
A condensate easily forms a polymerized product because the condensate contains no polymerization inhibitor. Thus, a polymerization inhibitor-containing liquid is sprayed on the tube plate 51 from the spray 52 through the polymerization inhibitor supply tube 53 for suppressing polymerization. Thus, formation of a polymerized product on the tube plate 51 is prevented. Further, the polymerization inhibitor-containing liquid flows into the cooling tube 56, to thereby supply the polymerization inhibitor to the condensate formed inside the cooling tube 56.
The above-mentioned conventional condenser is generally provided inside a condenser to avoid interference with a transportation operation or disassembly and cleaning operation of the condenser. However, an easily polymerizable compound may be condensed on a supporter, thereby a polymerized product may be formed.
To be more specific, a temperature of a liquid flowing through the polymerization inhibitor supply tube 53 being in contact with the supporter 54 or 55 is usually lower than a temperature of a gas containing an easily polymerizable compound supplied to the condenser 50. Thus, the supporter 54 or 55 is cooled and a condensate without a polymerization inhibitor is formed on the supporter 54 or 55, possibly a polymerized product may be formed.